fix(ios): fix text track selection by index (#3728)

* fix(ts): onPlaybackRateChangeData was not correctly typed

* fix: ensure tracks are well displayed in the sample

* fix(ios): text tracks selection by index. regression due to codegen rework

* chore: make selection by index testable (need a small manual patch)

* chore(ios): fix linter warning

ios/Video/DataStructures/SelectedTrackCriteria.swift

@@ -1,6 +1,6 @@
 struct SelectedTrackCriteria {
     let type: String
-    let value: Any?
+    let value: String?
 
     let json: NSDictionary?
 
@@ -13,6 +13,6 @@ struct SelectedTrackCriteria {
         }
         self.json = json
         self.type = json["type"] as? String ?? ""
-        self.value = json["value"]
+        self.value = json["value"] as? String
     }
 }